Jones said the hope is that Romo will be ready for offseason practices in May.
Romo missed all the offseason workouts this year after surgery to remove a cyst from his back in April. Garrett and Jones said the latest injury is not related, but wouldn't be more specific about Friday's procedure.
News of the second back surgery comes nine months after Romo signed a six-year, $108 million extension with $55 million guaranteed.
"He played very well coming off the first procedure he had in the spring," Garrett said. "We are completely confident he's going to rehab and come back 100 percent."
Orton, who declined to talk to reporters Friday, will make his first start since the finale in 2011, when he finished the season in Kansas City after getting replaced by Tim Tebow in Denver. He's appeared in three games and thrown just 15 passes in two seasons as Romo's backup.
"We've been operating as if Kyle Orton is going to be our starting quarterback," Garrett said. "At the same time we were trying to do whatever we could to see if we could help Tony and get him back as quickly as possible. We just felt like this was the best course of action."
Notes: DE DeMarcus Ware missed practice because of an elbow injury but told reporters he is playing. He's listed as questionable. ... WR/KR Dwayne Harris and CB Morris Claiborne are set to return from hamstring injuries. Both are probable. Harris missed three of the past four games, and Claiborne missed six of seven. ... LB Ernie Sims is doubtful with a groin injury.
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